The present invention relates to a motor-driven compressor having a compression mechanism, an electric motor and a motor driver circuit arranged in axial direction of a rotary shaft of the compressor.
There is known a motor-driven compressor having a compression mechanism, an electric motor and a motor driver circuit arranged in a housing in axial direction of a rotary shaft of the compressor. The motor driver circuit includes an inverter having a planar circuit board on which electronic components such as a switching device are mounted. The housing has on the outer surface thereof a cylindrical connector holder projecting outward at a position adjacent to the inverter. A connector having a bus bar electrically connected to the circuit board and an insulator holding the bus bar is provided in the connector holder.
When the connector holder extends from the housing in a direction perpendicular to the axial direction of the rotary shaft (hereinafter referred to as radial direction of the housing), the entire size of the compressor is increased in the radial direction. When the connector holder extends outward from the housing in radial direction at a position adjacent to the inverter and then along the axis of the rotary shaft in the direction away from the electric motor, the entire size of the compressor is increased in the axial direction of the rotary shaft. To prevent an increase of the entire size of the compressor as much as possible, for example, Japanese Unexamined Patent Application Publication No. 2009-74517 discloses a motor-driven compressor in which the connector holder extends radially outward from the housing at a position adjacent to the inverter and then extends along the axis of the rotary shaft toward the direction close to the electric motor.
In the arrangement of the compressor disclosed in the publication No. 2009-74517, the connector is provided in the axially extending cylindrical portion of the connector holder and the bus bar is also provided in the same portion of the connector holder. To connect the bus bar to the circuit board, part of the circuit board needs to be extended beyond the outer peripheral surface of the housing into the cylindrical portion, resulting in an increased size of the circuit board.
When the circuit board extends beyond the outer peripheral surface of the housing into cylindrical portion, the housing needs to have a large mounting hole for connection of such large circuit board to the bus bar and, therefore, a large cover for closing such large mounting hole needs to be provided. This results in an increased sealing area of the seal member for sealing between the cover and the housing.
The present invention is directed to providing a motor-driven compressor that allows a reduced sealing area of a seal member and a reduced size of a circuit board in the structure having a cylindrical portion extending toward the direction close to an electric motor.